Computer Health
Health is an indicator shown on the Computers list.
Health indicator icons are color coded and represent the single most serious problem detected on a host. They are shown in the Health column in Detail view.
Health is determined by Windows updates, anti-virus settings, and alerts
Health indicator icons:
The host requires reboot to finish the installation of important Windows updates or the Windows updates service is not running on the host. There is a critical issue with the anti-virus software. 
There is an issue with the anti-virus software, there are unacknowledged alerts, or the installation of important Windows updates is pending on the host.
The host is running the latest Windows updates, the most up-to-date virus definition, and there are no unacknowledged alerts.
Either you must update the host to see its full health report, or the anti-virus software is not fully supported.